Contessa's at the same moment. There was no reason why she should not
have looked at him just then, but he rested one elbow on the table and
shaded his eyes from the light.

"It is strange to reflect," said Kalmon, looking at the tube
thoughtfully, "that one of those little things would be enough to put a
Hercules out of misery, without leaving the slightest trace which
science could discover."

Corbario was still shading his eyes from the light.

"How would one die if one took it?" asked Aurora. "Very suddenly?"

"I call it the sleeping death," answered the Professor. "The poisoned
person sinks into a sweet sleep in a few minutes, smiling as if enjoying
the most delightful dreams."

"And one never wakes up?" inquired Marcello.

"Never. It is impossible, I believe. I have made experiments on animals,
and have not succeeded in waking them by any known means."

"I suppose it congests the brain, like opium," observed Corbario,
quietly.

"Not at all, not at all!" answered Kalmon, looking benevolently at the
little tube which contained his discovery. "I tell you it leaves no
trace whatever, not even as much as is left by death from an electric
current. And it has no taste, no smell,--it seems the most innocent
stuff in the world."